Tongue Tie and Frenotomy in the Breastfeeding Newborn Isabella Knox, MD, Edm* Abstract Tongue Tie Or Ankyloglossia Has Been the Subject of Much Controversy
Total Page:16
File Type:pdf, Size:1020Kb
Article surgery Tongue Tie and Frenotomy in the Breastfeeding Newborn Isabella Knox, MD, EdM* Abstract Tongue tie or ankyloglossia has been the subject of much controversy. As defined in Author Disclosure this review, tongue tie occurs when a common minor embryologic tissue remnant— Dr Knox has disclosed persistence of midline sublingual tissue that usually undergoes apoptosis during no financial embryonic development—causes restriction of normal tongue movement. Effective breastfeeding requires newborns to fine-tune their tongue movements to adapt to relationships relevant their mothers’ particular nipple and breast anatomy and physiology. In the presence of to this article. This tongue tie, two categories of signs/symptoms arise: those related to nipple trauma and commentary does not those related to ineffective breast emptying and low infant intake. Untreated tongue contain a discussion tie can lead to untimely weaning and its attendant health risks. Frenotomy is a safe and of an unapproved/ effective procedure to release tongue tie and improve tongue function and breastfeed- investigative use of a ing outcomes. commercial product/ device. Objectives After completing this article, readers should be able to: 1. Recognize the existence of tongue tie as a condition that can potentially cause clinical dysfunction. 2. Understand the pathophysiologic mechanisms of clinical signs and symptoms of tongue tie in a breastfeeding dyad. 3. Determine when to refer a breastfeeding infant for frenotomy. Introduction Tongue tie, also known as ankyloglossia, occurs when a persistent lingual frenum restricts tongue movements and interferes with tongue function. True ankyloglossia is classified as a minor congenital anomaly. (1) Controversy has existed for centuries about if and when sublingual frenum tissue is the actual cause of clinical dysfunction. Over the past 3 decades, advances have been made in defining the embryology, pathophysiology, clinical features, and treatment of tongue tie. It is now clear that in some cases sublingual frenum tissue causes tongue tie because the tissue is restrictive and creates difficulties with breastfeeding and, later in life, other activities that require tongue mobility. The field is still hampered by the lack of a uniform definition, diagnostic criteria, treatment indications, and outcomes research. This review summarizes current knowledge about tongue tie in 2010. History Tongue tie is mentioned in the Bible and other written documents that precede the modern medical literature. (2)(3) For many centuries, it was believed that the sublingual frenum could impair an infant’s ability to extract milk from the breast and, hence, to survive. Frenotomy was widely practiced by midwives and physicians until the mid-20th century, coinciding with the period in which few infants in the United States were breastfed. (4) Tongue tie rarely causes major dysfunction in bottlefeeding infants, and it was not until the early 1990s, after breastfeeding rates had risen significantly, that tongue tie and frenotomy reappeared in the medical literature. Tongue tie is now confirmed as a relatively common and remediable clinical entity, (5)(6)(7)(8) although many important clinical questions remain. In 2010, all neonatologists, general pediatricians, and family physicians should understand this entity and ensure that resources are available to their patients for diagnosis and remediation. *Department of Pediatrics, Division of Neonatology, University of Washington, Seattle, Wash. NeoReviews Vol.11 No.9 September 2010 e513 surgery frenotomy Embryology Between the fourth and seventh weeks of development, the oral cav- ity of the embryo develops from a smooth-walled tube to a more ma- ture structure that has complex anatomy, including a mobile, mus- cular tongue that protrudes freely from the floor of the mouth (Fig. 1). The tongue develops from bilat- eral tissue buds that grow from the inner surface of the oral tube, fuse posteriorly-to-anteriorly, and sepa- rate from the floor of the mouth. As with many processes in embryo- logic development, the separation occurs by a combination of tissue growth and programmed morpho- logic cell death (apoptosis). Similar to interdigital synechiae seen in soft-tissue syndactyly, (9) the per- Figure 1. Embryology of tongue development. A. and B. Scanning electron micrographs of sistent lingual frenum is likely a mouse embryo at days 10 and 12, respectively, approximately equivalent to human weeks remnant of incomplete apoptosis. 5 and 7. Courtesy of K. K. Sulik, all rights reserved. C. and D. Corresponding mid-sagittal (10)(11) This anomaly most com- anatomy. Drawn by Kelly Ledbetter, © 2010, University of Washington. E. and F. monly occurs in isolation. Its asso- Corresponding coronal sections through the anterior tongue. ciation with cleft palate has been well characterized, including iden- Terminology tification of an underlying TBOX gene abnormality in some kindreds. Frenum A membranous fold of skin or mucous membrane (12) Other anomalies have been (or frenulum): that supports or restricts the movement of a part of organ. associated with tongue tie, most Persistent lingual Presence of a frenum between the underside of the often involving craniofacial struc- frenum: tongue and the floor of the mouth; this does not tures. Maternal cocaine use has necessarily cause clinical dysfunction. been documented as a risk factor Tongue tie: Restriction of tongue movement or function by a for tongue tie. (13) persistent lingual frenum. Note that some authors use “tongue tie” to refer to the presence of any sublingual tissue. In this article, a clear distinction is made between Epidemiology frenum tissue, which may be present and in no way interfere The incidence of tongue tie is diffi- with tongue function, and tongue tie, in which the frenum cult to ascertain because of the lack is restrictive. of a uniform assessment strategy. Ankyloglossia: Synonym for tongue tie. Studies that rely on visual inspec- Frenotomy Surgical procedure in which the frenum is incised. tion alone report a rate of persistent (or frenulotomy): lingual tissue of 3% to 10%. (5)(8) Frenectomy Surgical procedure in which frenum tissue is excised. Several studies have attempted to (or frenulectomy): assess the risk that the presence of this tissue poses for breastfeeding e514 NeoReviews Vol.11 No.9 September 2010 surgery frenotomy difficulties (ie, tongue tie) but are complicated by the proper relationship with the hard and soft palates, the large numbers needed and the many factors involved in tongue itself, and the swallowing/breathing apparatus. breastfeeding success. The risk appears to be significant, 3. Produce the intraoral vacuum that results in milk in the range of 25% to 60%. (14) In most studies, a flow from the breast. (17) male:female ratio of about 2:1 has been reported, al- Restriction of the tongue’s ability to move freely leads to though Knox and O’Callahan recently reported the first suboptimal nursing mechanics. The nipple’s spatial rela- large series of posterior tongue ties and found a male: tionship to the infant’s mouth structures and the specific female ratio of 1:1. (15) pattern of tongue movements are critical both for effec- Pathophysiology tive and efficient milk removal and for protection of the delicate nipple tissue from trauma. The downstream Complex tongue movements are critical for successful effects of tongue tie are related either to ineffective breast breastfeeding. Each mother and baby have unique ana- emptying or to nipple trauma. All of the common signs tomic features, and the infant must adapt his or her and symptoms of tongue tie can be explained by the sucking behavior accordingly. To extract milk success- effects of abnormal sucking mechanics (Table). fully, the tongue must undertake several actions (Fig. 2 and Video 1 in data supplement): 1. Protrude over the alveolar ridge both to inhibit the Diagnostic Features bite reflex (16) and to contribute to an airtight seal on In addition to the clinical signs and symptoms listed in the areola that allows creation of an intraoral vacuum. Table, the diagnosis of tongue tie is based on anatomic 2. Manipulate the nipple and areolar tissue into the and functional abnormalities found on physical exami- nation. The physical examination may reveal either a thin anterior membrane or a thick posterior fi- brous strand in the midline be- tween the underside of the tongue and the floor of the mouth (Fig. 3). The superior attachment of the fre- num to the tongue can occur in various locations between the tip and the junction with the floor of the mouth. On occasion, no abnor- mality is visible. Instead, a tight midline filament, like a taut fishing line in the soft tissue where the tongue joins the floor of the mouth, is palpable. In general, an- terior frena are thin and trans- parent, merely consisting of a re- flection of mucosal tissue, while posterior frena are thicker, white, and fibrous-looking. Occasionally, blood vessels or muscle fibers may be present in the frenum. Assessment of newborn tongue function is challenging, particularly during nursing, when most struc- Figure 2. During nursing, the infant’s tongue must: 1) protrude over the alveolar ridge to inhibit the bite reflex, 2) assist the flanged lips in maintaining an airtight seal on the tures are not visible. Because mater- areola, 3) with its prehensile function, manipulate the nipple into the proper position nal characteristics also contribute to (note the depth of the nipple tip and its proximity to the hard-soft